Performance Analysis of UDRE Estimation for Maritime Differential GPS

Abstract

Maritime differential GPS has been widely used for the enhancement of GPS positioning performance due to a little burden on transmitting the correction data and the easiness of correction processing to improve the position accuracy. Over the next few years, planning re-equipment and replacing the equipment of maritime DGPS service are needed owing to re-capitalization periods for such equipment. And re-capitalized maritime DGPS are required to meet all the minimum maritime user requirements presented in IMO Resolution A.915(22) as well as the standards recently suggested by RTCM and to include future GNSS improvements such as use of Galileo, GLONASS M, and new civil frequencies and codes on GPS L2, L5. Particularly, IMO Resolution A.915(22) emphasizes that the future maritime DGPS should meet the better performance of integrity monitoring. For this reason, this paper deals with the UDRE(User Differential Range Error) estimation and performance analysis for maritime DGPS because the UDRE directly affects the capability of integrity monitoring. Firstly, in order to extract the UDRE requirements for maritime DGPS, this paper carries out a study to analyze the standards recently suggested by RTCM. And a live satellite based performance analysis method is proposed to achieve the reasonable analysis results from the standpoint of the extracted requirements for maritime navigation. It is presented that the proposed performance analysis method using IGS(International GNSS Service) data can be applied to the accurate and more realistic testing in contrast with the existing testing using GPS simulator. Finally this paper shows that the proposed method can be applied to the accurate and more realistic analysis.